// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/process/process_metrics.h"

#include <limits.h>
#include <stddef.h>
#include <stdint.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <unistd.h>

#include "base/logging.h"
#include "build/build_config.h"

namespace base {

int64_t TimeValToMicroseconds(const struct timeval& tv)
{
    int64_t ret = tv.tv_sec; // Avoid (int * int) integer overflow.
    ret *= Time::kMicrosecondsPerSecond;
    ret += tv.tv_usec;
    return ret;
}

ProcessMetrics::~ProcessMetrics() { }

#if defined(OS_LINUX)
static const rlim_t kSystemDefaultMaxFds = 8192;
#elif defined(OS_MACOSX)
static const rlim_t kSystemDefaultMaxFds = 256;
#elif defined(OS_SOLARIS)
static const rlim_t kSystemDefaultMaxFds = 8192;
#elif defined(OS_FREEBSD)
static const rlim_t kSystemDefaultMaxFds = 8192;
#elif defined(OS_OPENBSD)
static const rlim_t kSystemDefaultMaxFds = 256;
#elif defined(OS_ANDROID)
static const rlim_t kSystemDefaultMaxFds = 1024;
#endif

size_t GetMaxFds()
{
    rlim_t max_fds;
    struct rlimit nofile;
    if (getrlimit(RLIMIT_NOFILE, &nofile)) {
        // getrlimit failed. Take a best guess.
        max_fds = kSystemDefaultMaxFds;
        RAW_LOG(ERROR, "getrlimit(RLIMIT_NOFILE) failed");
    } else {
        max_fds = nofile.rlim_cur;
    }

    if (max_fds > INT_MAX)
        max_fds = INT_MAX;

    return static_cast<size_t>(max_fds);
}

void SetFdLimit(unsigned int max_descriptors)
{
    struct rlimit limits;
    if (getrlimit(RLIMIT_NOFILE, &limits) == 0) {
        unsigned int new_limit = max_descriptors;
        if (limits.rlim_max > 0 && limits.rlim_max < max_descriptors) {
            new_limit = limits.rlim_max;
        }
        limits.rlim_cur = new_limit;
        if (setrlimit(RLIMIT_NOFILE, &limits) != 0) {
            PLOG(INFO) << "Failed to set file descriptor limit";
        }
    } else {
        PLOG(INFO) << "Failed to get file descriptor limit";
    }
}

size_t GetPageSize()
{
    return getpagesize();
}

} // namespace base
